There are tons of info about SAKE (an alcoholic beverage of Japanese origin that is made from fermented rice. ref Wikipedia) But info about just to enjoy of SAKE easily are really few. Here SSI INTERNATIONAL made 21,000 types of tasting through several years and classified into 4 types to enjoy SAKE easily. (All the SAKE would not categorised in this. It's just the general tendency)
It seems it doesn't have English ver. so I extracted and as simplified here below in English.